If your body insists on nagging at you with a pain here and a pain there, you must try the thermal baths in San Juan Cosalá, specifically Balneario Spa & Thermal Bath, just by the shore.

But beware of the topes. Driving there should become an Olympic event. The westward stretch of road is a tope slalom. I feel I’ve made a successful trip if I get there and back and still have all four wheels pointing in the same direction. The topes really can pop up unexpectedly. (“Is that a tope up ahead or are they just glad to see me.”)

Should you not see a steep tope if you’re speeding along, you could actually achieve lift-off high enough to appear for a moment on radar at the airport, scaring the hell out of air traffic control. I’ve done it. My passengers all applauded when we landed.

Once at the thermal baths, you will find that there are several pools of water at differing temperatures, and a huge area for children with tubular slides and diving boards. But the key attraction is the giant roundeville basin filled with water as hot as 44 degrees Celsius, 112 degrees Fahrenheit. It is recommended that one stay in this hot tub no longer than 10 minutes, or else your internal organs will look like a pozole.

The fuel that heats this roundeville comes up from a steaming hot aquifer, boiling over from something blazing below the Earth’s mantle, and if one listens very, very closely, one can hear vague screaming, “I didn’t mean to vote for that idiot. I was scammed!” or “All I said was, ‘Honey, have you considered breast augmentation?’” These echoes could be really scary. They’re probably the reason they recommend you stay in the hot tub no longer than ten minutes.

Nonetheless, the spa is almost always packed with visitors. The belief is that the minerals in the baths are healthful: sulfur, magnesium, aluminum, cobalt, and I’m sure I detected a pinch of oregano. These, most visitors believe, find ways into your body and heal it with no side effects, except for the occasional dizziness from the Uranium 235 (I made that up). Even though the science says that these trace minerals have no healing effects on the body, there is always the placebo effect. The placebo effect is your imagination’s way of curing you of whatever ails you with a TicTac.

Now, how these thermal waters do create genuine healthfulness, according to the latest studies, are the effects of the unusually high temperatures on the body. These have a soothing and relaxing effect on all corporeal systems, especially blood flow, metabolism and tense muscles. In short, it’s like a long hot bath in your tub.

Yet, despite this theory, I still believe I’m getting my cobalt fix. I know this because I’m not eating anything labeled “packed with your daily requirement of cobalt.”

In any case, other spa services are a steaming hot sauna cave, mud baths, massages, jacuzzi pools, large swim pools and lunch served at your table. So, while the fire and brimstone burn below, you have a heaven flirting all around you above.

So where do these amazing waters come from?

It is no accident that San Juan Cosalá has some very peculiar weather. The trombas, for instance. These are intense tornadoes of water and mud that come down from the mountains and move a cow pasture into your living room, sometimes with the cows. They are violent and occur in the area of the thermal waters on a regular basis.

The whole Lake Chapala area is part of Mexico’s “Volcanic Axis,” which was tectonically active millions of years ago. According to geologists, the entire Lake Chapala valley eons ago was an enormous volcanic pit, a caldera. And it’s still fused with the geothermal oven deep under the Earth’s mantle. There are hot springs on each end of the lake as proof. So, if you see a particularly deep pothole on Ajijic’s Calle de Revolucion, and it’s smoking, it could be a lava flow.